Synchronous optical network (SONET) is a standard for optical telecommunications that provides the transport infrastructure for worldwide telecommunications. SONET offers cost-effective transport both in the access area and core of the network. For instance, telephone or data switches rely on SONET transport for interconnection.
In a typical application, a local area network (LAN), such as Ethernet, is connected to a wide area network (WAN), such as that provided by SONET. The LAN and WAN may be interfaced by a device known as a LAN Service Unit (LANSU), which has ports for connecting the LAN and ports for connecting the WAN. In many applications, the LAN input bandwidth to the LANSU may be greater than the LANSU backplane bandwidth or the WAN bandwidth that the system has to offer. If the traffic on the LAN requires greater bandwidth than the LANSU backplane or WAN can provide, traffic may be lost and serious degradation of performance may result. Proliferation of ever faster LAN technologies makes this situation even more likely. A need arises for a technique by which LANSU backplane bandwidth can be increased to handle increased LAN traffic bandwidth that is inexpensive and that avoids the performance degradation that may otherwise result.